package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

/**
 * 全局唯一ID生成器
 */
@Component
public class RedisIdWorker {

    /**
     * 开始时间戳
     */
    private static final long BEGIN_TIMESTAMP = 1741651200L;
    /**
     * 序列号位数
     */
    private static final int COUNT_BITS = 32;


    private StringRedisTemplate stringRedisTemplate;

    public RedisIdWorker(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public long nextId(String keyPrefix) {
        //1.生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        //2.生成序列号
        //2.1 获取当前日期,精确到天
        String date = now.format(DateTimeFormatter.ofPattern("yyyyMMdd"));
        //2.2 自增长
        Long count = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        //3.拼接并返回
        return timestamp <<COUNT_BITS | count;//或运算: 一个为真就为真


    }

    public static void main(String[] args) {
        LocalDateTime time = LocalDateTime.of(2025, 3, 11, 0, 0);
        long second = time.toEpochSecond(ZoneOffset.UTC);
        System.out.println("second = "+second);
    }
}
